ABSTRACT:The global trend of urbanization is concentrating humans in cities, making them major centers of biogeochemical cycling. The role of individual households and how their decisions affect their surrounding ecosystems have been largely ignored, in favor of analysis of large scale entities, such as industry or agriculture. We developed a mathematical computer model (Household Flux Calculator, HFC) that calculates the fluxes of elemental carbon (C), nitrogen (N), and phosphorus (P) for individual households based on a variety of household behaviors and decisions, such as energy use, transportation, diet, and lawn management practices. Preliminary results for realistic low, typical, and high consumption scenarios in the United States show that for households of similar compositions and socio-economic backgrounds, household C flux may vary by a factor of five, household N by a factor of three and household P by a factor of two. This implies that amenity choices - choices made within the bounds of the modern urban/suburban lifestyle - have a major influence on fluxes of C, N, and P. The HFC model was used to analyze real-world information collected from two sets of household interview pilot studies; one in Falcon Heights, Minnesota, an upper-middle class first-ring suburb of the Twin Cities and the second in Tirana, Albania, a rapidly growing large city in a developing nation. The resulting fluxes of household C, N, and P show considerable variation both within and between each sample group, particularly on a per capita basis.